Question

A parallel plate capacitor filled with a material of dielectric constant k is charged to a certain voltage. The dielectric material is removed. Then:

• A. A and B are true
• B. A and C are true
• C. B and C are true
• D. B and D are true

Answer 1

Answer: (A)

As capacitance of capacitor after introducing dielectric is given by $C=\frac{k{\epsilon }_{0}A}{d}$ Hence, if dielectric is introduced the capacitance increases by k, but when dielectric is removed, then capacitance will decrease by factor k and since $V=\frac{Q}{C}$ Hence, if C decreases in factor k then V will increase by factor k.